KR20220032586A - optical film - Google Patents

Abstract

The present invention provides an optical film which is excellent in the adhesiveness between a resin substrate and an optically anisotropic layer, and in which generation|occurrence|production of the optical defect was suppressed in the optically anisotropic layer. The optical film of the present invention is an optical film having a resin substrate having an orientation regulating force and an optically anisotropic layer disposed on the resin substrate, wherein the optically anisotropic layer is a liquid crystal compound and a compound having a heteroatom different from the liquid crystal compound Including, making the surface of the optically anisotropic layer side of the optical film the first surface, the surface of the resin substrate side of the optical film as the second surface, from the first surface toward the second surface side, while irradiating an ion beam When the component in the depth direction of the optical film is analyzed by the time-of-flight secondary ion mass spectrometry, the obtained profile satisfies a predetermined requirement.

Description

optical film

The present invention relates to an optical film.

DESCRIPTION OF RELATED ART The optically anisotropic layer which has refractive index anisotropy is applied to various uses, such as an antireflection film of a display device, and an optical compensation film of a liquid crystal display device.

In Patent Document 1, as a method of forming an optically anisotropic layer, a rubbing treatment is performed on a resin substrate, and a composition containing a liquid crystal compound is applied on the surface thereof to form an optically anisotropic layer is disclosed.

Japanese Patent Laid-Open No. 2014-182217

On the other hand, in recent years, the further improvement of the adhesiveness between a resin base material and an optically anisotropic layer is calculated|required. According to examination by the present inventors, in the aspect disclosed by patent document 1, the adhesiveness between a resin base material and an optically anisotropic layer was not enough, and it discovered that further improvement was needed.

Moreover, in the optically anisotropic layer to be formed, it is also desired that generation|occurrence|production of the optical defect resulting from the orientation defect of a liquid crystal compound be suppressed.

In view of the above situation, an object of the present invention is to provide an optical film excellent in the adhesiveness between the resin substrate and the optically anisotropic layer and in which the occurrence of optical defects in the optically anisotropic layer is suppressed.

MEANS TO SOLVE THE PROBLEM The present inventors discovered that the said subject could be solved by the following structures, as a result of earnestly examining about the problem of a prior art.

(1) an optical film having a resin substrate having an orientation regulating force, and an optically anisotropic layer disposed on the resin substrate,

The optically anisotropic layer contains a liquid crystal compound and a compound having a hetero atom different from the liquid crystal compound,

The surface of the optical film on the side of the optically anisotropic layer is the first surface, the surface of the optical film on the resin substrate side is the second surface, and the time-of-flight type 2 while irradiating an ion beam from the first surface to the second surface side The optical film which satisfies both the requirements 1 and 2 mentioned later, when the component of the depth direction of an optical film is analyzed by differential ion mass spectrometry.

(2) The optical film according to (1), wherein the compound having a hetero atom has at least one selected from the group consisting of a urethane group, an ester group, an amide group, and a boronic acid group.

(3) the optically anisotropic layer,

A liquid crystal compound having a polymerizable group;

The optical film as described in (1) or (2) which is a layer formed using the composition which is different from the liquid crystal compound which has a polymeric group, and contains the polymeric compound which has a hetero atom and has a polymerizable group.

(4) The optical film according to (3), wherein the polymerizable compound having a hetero atom and a polymerizable group includes a repeating unit having a polymerizable group and is a polymer having a hetero atom.

(5) When the average intensity of the secondary ionic strength derived from the compound having a hetero atom from the first surface to the A position is taken as the average value Iave, the maximum value Imax and the average value Iave satisfy the relationship of formula (A) , The optical film according to any one of (1) to (4).

Equation (A) 1.3≤Imax/Iave

(6) The optical film as described in (5) whose Imax/Iave is 50 or more.

(7) The optical film according to any one of (1) to (6), wherein the distance between the C position and the D position is 50 nm or less.

(8) The optical film in any one of (1)-(7) in which a resin base material contains a cellulose acylate.

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in the adhesiveness between a resin base material and an optically anisotropic layer, and can provide the optical film by which generation|occurrence|production of the optical defect was suppressed in the optically anisotropic layer.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of an optical film.
2 is a schematic diagram for explaining a depth direction profile of secondary ion intensity derived from each component detected by analyzing the components in the depth direction of the optical film by time-of-flight secondary ion mass spectrometry (TOF-SIMS).
It is sectional drawing of the composition layer for demonstrating process A.
It is sectional drawing of the composition layer for demonstrating process B.
Figure 5 shows the relationship between helical twisting power (HTP) (μm ^-1 ) × concentration (mass %) and light irradiation dose (mJ/cm ² ) for each of chiral agent A and chiral agent B; It is a schematic diagram of the plotted graph.
6 is a schematic diagram of a graph plotting the relationship between the weighted average helical organic force (μm ⁻¹ ) and the amount of light irradiation (mJ/cm ² ) in a system in which the chiral agent A and the chiral agent B are used in combination. .
It is sectional drawing of the composition layer for demonstrating the case where process E is implemented.

Hereinafter, the present invention will be described in detail. In addition, in this specification, the numerical range shown using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit. First, the terms used in this specification will be described.

"Light" in this specification means actinic ray or radiation, for example, the bright-ray spectrum of a mercury vapor lamp, the deep ultraviolet ray represented by excimer laser, extreme ultraviolet (EUV light: Extreme Ultraviolet), X-ray, an ultraviolet-ray, and, an electron beam (EB). Among them, ultraviolet rays are preferable.

In this specification, "visible light" refers to light of 380 to 780 nm. In addition, in this specification, when there is no note in particular about a measurement wavelength, a measurement wavelength is 550 nm.

In this specification, when the liquid crystal compound is torsionally oriented in the optically anisotropic layer, it is preferable that the twist angle is more than 0 degree and less than 360 degrees.

In this specification, "(meth)acryl" is a generic term for acryl and methacryl, and "(meth)acrylate" is a generic term for acrylate and methacrylate.

In the present invention, Re(λ) and Rth(λ) represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. Unless otherwise specified, the wavelength λ is 550 nm.

In the present invention, Re(λ) and Rth(λ) are values measured at a wavelength λ by AxoScan, manufactured by Axometrics. By inputting the average refractive index ((nx+ny+nz)/3) and the film thickness (d(μm)) into AxoScan,

Slow axis direction (°)

Re(λ)=R0(λ)

Rth(λ)=((nx+ny)/2-nz)×d

is calculated

In addition, although R0(λ) is expressed as a numerical value calculated by AxoScan, it means Re(λ).

In the present specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) and a sodium lamp (λ=589 nm) as a light source. In addition, when measuring wavelength dependence, it can measure with the multi-wavelength Abbe refractometer DR-M2 (made by Atago Co., Ltd.) in combination with an interference filter.

Moreover, the values of the catalog of a polymer handbook (JOHN WILEY & SONS, INC) and various optical films can be used. The values of the average refractive index of the main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethylmethacrylate (1.49), and polystyrene (1.59).

As a characteristic point of the optical film of the present invention, in the depth direction of the optical film, a compound having a hetero atom (hereinafter also simply referred to as a "specific compound") is distributed at a predetermined depth position.

Requirement 1 to be described later means that a specific compound is unevenly distributed on the resin substrate side in the optically anisotropic layer, and by satisfying the requirement 1, the adhesion between the resin substrate and the optically anisotropic layer is improved.

Requirement 2 to be described later indicates the localized amount of a specific compound, and by satisfying requirement 2, the alignment property of the liquid crystal compound is ensured, and generation of optical defects is suppressed.

Hereinafter, one Embodiment of an optical film is described using drawings.

1 : is schematic which shows an example of an optical film. The optical film 10 has the resin substrate 12 and the optically anisotropic layer 14 in this order. As shown in FIG. 1 , the resin substrate 12 and the optically anisotropic layer 14 are in direct contact with each other.

Hereinafter, each member which comprises an optical film is demonstrated in detail.

<Resin substrate>

The optical film has a resin base material.

The resin substrate has an orientation regulating force. That the resin substrate has an orientation regulating force means that it has a force to orient the liquid crystal compound when the liquid crystal compound is disposed on the surface of the resin substrate. That is, the resin substrate has an orientation regulating force with respect to the liquid crystal compound.

As a resin base material which has the said orientation regulating force, the resin base material to which the rubbing process was given, and the resin base material to which the extending|stretching process was given are mentioned, for example, The resin base material to which the rubbing process was given is preferable.

The direction in particular of a rubbing process is not restrict|limited, According to the direction to orientate a liquid crystal compound, an optimal direction is selected suitably.

The rubbing process can apply the processing method widely employ|adopted as a liquid-crystal orientation processing process of LCD (liquid crystal display). That is, a method of obtaining orientation by rubbing the surface of the resin substrate in a certain direction using paper, gauze, felt, rubber, nylon fiber, or polyester fiber or the like can be used.

As a resin base material, a transparent base material is preferable. In addition, the transparent base material intends the base material whose transmittance|permeability of visible light is 60 % or more, 80 % or more of the transmittance|permeability is preferable, and 90 % or more is more preferable.

As the resin constituting the resin substrate, a polymer excellent in optical performance, transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, and the like is preferable.

As a resin base material, For example, a cellulose acylate film (for example, a cellulose triacetate film (refractive index 1.48), a cellulose diacetate film, a cellulose acetate butylate film, a cellulose acetate propionate film), a polyolefin film (for example, For example, polyethylene film and polypropylene film), polyester film (for example, polyethylene terephthalate film and polyethylene naphthalate film), polyacrylic film (for example, polymethyl methacrylate), polyethersulfone film, Polyurethane film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, (meth)acrylnitrile film, and polymer film having an alicyclic structure (Novo Nene resin (Aton: brand name, JSR company make, amorphous polyolefin (Zeonex: brand name, Nippon Zeon company make)) is mentioned.

Among them, as the resin constituting the resin substrate, at least one effect is obtained from the superior adhesion between the resin substrate and the optically anisotropic layer, and the more suppressed occurrence of optical defects in the optically anisotropic layer (hereinafter, simply Also referred to as "the point where the effect of the present invention is more excellent."), cellulose acylate, poly(meth)acrylate, a polymer having an alicyclic structure, polystyrene, or polycarbonate is preferable, and cellulose acylate is more preferable. Do.

The resin substrate may contain various additives (for example, an optical anisotropy modifier, a wavelength dispersion modifier, fine particles, a plasticizer, an ultraviolet inhibitor, a deterioration inhibitor, and a release agent).

Although the in-plane retardation in particular in wavelength 550nm of a resin base material is not restrict|limited, From the point which it is easy to exhibit the optical characteristic of an optically anisotropic layer more, 10 nm or less is preferable. Although a lower limit in particular is not restrict|limited, 0 is mentioned.

Although the SP (Solubility Parameter) value in particular of a resin base material is not restrict|limited, 19.0-25.0 MPa ^1/2 is preferable, and 20.0-23.0 MPa ^1/2 is more preferable.

In addition, the SP value of a resin base material corresponds to the SP value of resin which comprises a resin base material.

In the present specification, the SP value refers to the non-dispersive force component δa of the SP value calculated by the method of Hoy et al. (VAN KREVELEN, DW, "PROPERTIES OF POLYMERS (ED. 3)" ELSEVIER publication (1990)) do.

That is, the δa value can be calculated by the following formula (X) using the three-dimensional SP values (δd, δp, δh) calculated by the method of Hoy et al.

δa=(δp ² +δh ² ) ^0.5 Equation (X)

According to the method of Hoy et al., each value of δd, δp, and δh can be calculated from the chemical structural formula of the compound to be obtained.

In addition, in the case of a copolymer consisting of a plurality of repeating units, the square value (δd ² , δp ² , δh ² ) of the three-dimensional SP value of each repeating unit is multiplied by the volume fraction of each repeating unit to obtain a sum. The δa value of the copolymer can be obtained by calculating the square value (δd ² , δp ² , δh ² ) of the three-dimensional SP value of and substituting this into the above formula (X).

Although the thickness in particular of a resin base material is not restrict|limited, 10-200 micrometers is preferable, 10-100 micrometers is more preferable, 20-90 micrometers is still more preferable.

<Optical anisotropic layer>

(liquid crystal compound)

The optically anisotropic layer contains a liquid crystal compound.

The kind in particular of a liquid crystal compound is not restrict|limited, A well-known liquid crystal compound is mentioned.

As a liquid crystal compound, a low molecular weight compound may be sufficient and a high molecular compound may be sufficient. The low molecular weight compound means a compound having a molecular weight of 1000 or less, and the high molecular weight compound means a compound having a molecular weight greater than 1000.

It is preferable that the liquid crystal compound contained in the optically anisotropic layer is a high molecular compound.

Although content in particular of the liquid crystal compound in an optically anisotropic layer is not restrict|limited, From the point which the effect of this invention is more excellent, 50 mass % or more is preferable with respect to the total mass of an optically anisotropic layer, and 70 mass % or more is more preferable. . Although the upper limit in particular is not restrict|limited, 90 mass % or less in many cases.

From the viewpoint of more excellent effects of the present invention, the optically anisotropic layer is preferably formed using a composition containing a liquid crystal compound having a polymerizable group (hereinafter, also referred to as a "polymerizable liquid crystal compound"). In other words, the liquid crystal compound contained in the optically anisotropic layer is preferably a polymer obtained by polymerizing the polymerizable liquid crystal compound.

The kind in particular of a polymeric liquid crystal compound is not restrict|limited. In general, the liquid crystal compound can be classified into a rod-shaped type (a rod-shaped liquid crystal compound) and a disk-shaped type (a discotic liquid crystal compound) from the shape thereof. In addition, the liquid crystal compound can be classified into a low molecular type and a high molecular type. A polymer generally refers to a polymer having a degree of polymerization of 100 or more (Physical/Phase Change Dynamics of Polymers, Masao Doi, p. 2, Iwanami Shoten, 1992). Although any liquid crystal compound may be used in this invention, it is preferable to use a polymerizable rod-shaped liquid crystal compound or a polymerizable disk-shaped liquid crystal compound, and it is more preferable to use a polymerizable rod-shaped liquid crystal compound. Two or more types of polymerizable rod-shaped liquid crystal compounds, two or more types of polymerizable disk-shaped liquid crystal compounds, or a mixture of a polymerizable rod-shaped liquid crystal compound and a polymerizable disk-shaped liquid crystal compound may be used.

Moreover, as a polymerizable rod-shaped liquid crystal compound, the thing of Paragraph 0026 - 0098 of Unexamined-Japanese-Patent No. 11-513019 or Paragraph 0026 of Unexamined-Japanese-Patent No. 2005-289980 can be used suitably, for example.

As a polymerizable discotic liquid crystal compound, the thing of Paragraph 0020 - 0067 of Unexamined-Japanese-Patent No. 2007-108732 or Paragraph 0013 - 0108 of Unexamined-Japanese-Patent No. 2010-244038 can be used preferably, for example.

The kind of polymerizable group in the polymerizable liquid crystal compound is not particularly limited, and a functional group capable of addition polymerization reaction is preferable, a polymerizable ethylenically unsaturated group or a ring polymerizable group is more preferable, and acryloyl group, methacryloyl group, vinyl group, or a styryl group is more preferable.

(compounds with heteroatoms)

The optically anisotropic layer contains a compound (specific compound) having a hetero atom different from the above-mentioned liquid crystal compound. As will be described later, the specific compound is distributed at a predetermined position in the optical film.

A specific compound has a hetero atom. When a specific compound has a hetero atom, the adhesiveness of a base material and an optically anisotropic layer improves. As a hetero atom, an oxygen atom, a nitrogen atom, a sulfur atom, or a boron atom is preferable at the point which the effect of this invention is more excellent.

It is preferable that a specific compound has at least one selected from the group which consists of a urethane group, an ester group, an amide group, and a boronic acid group from the point which the effect of this invention is more excellent.

As a specific compound, a low molecular weight compound may be sufficient and a high molecular compound may be sufficient. The low molecular weight compound means a compound having a molecular weight of 1000 or less, and the high molecular weight compound means a compound having a molecular weight greater than 1000.

It is preferable that the specific compound contained in the optically anisotropic layer is a high molecular compound.

The content of the specific compound in the optically anisotropic layer is not particularly limited, but from the viewpoint of more excellent effects of the present invention, it is preferably 10% by mass or less, and more preferably 5% by mass or less, with respect to the total mass of the optically anisotropic layer. , 2 mass % or less is more preferable. Although a lower limit in particular is not restrict|limited, 0.1 mass % or more is preferable, and 0.3 mass % or more is more preferable.

It is preferable that the optically anisotropic layer is formed using the composition containing the polymeric compound which has a polymeric group while having a hetero atom from the point which the effect of this invention is more excellent. In other words, the specific compound contained in the optically anisotropic layer is preferably a polymer obtained by polymerizing a polymerizable compound having a hetero atom and a polymerizable group (hereinafter also referred to as “specific polymerizable compound”).

A specific polymeric compound has a hetero atom.

As a hetero atom, an oxygen atom, a nitrogen atom, a sulfur atom, or a boron atom is preferable at the point which the effect of this invention is more excellent.

The specific polymerizable compound preferably has at least one selected from the group consisting of a urethane group, an ester group, an amide group, and a boronic acid group (-B(OH) ₂ ) from the viewpoint of more excellent effects of the present invention Do.

The specific polymerizable compound contains a repeating unit having a polymerizable group (hereinafter also referred to as “unit 1”) from the viewpoint of better adhesion between the resin substrate and the optically anisotropic layer, and a polymer having a hetero atom (hereinafter simply referred to as “unit 1”). It is also referred to as "specific polymerizable polymer").

The kind of hetero atom which specific polymeric polymer|macromolecule has is as above-mentioned.

It is preferable that a specific polymeric polymer has at least one selected from the group which consists of a urethane group, an ester group, an amide group, and a boronic acid group from the point which the effect of this invention is more excellent.

As will be described later, the specific polymerizable polymer may have a hetero atom in the unit 1.

The kind of polymerizable group in unit 1 is not particularly limited, and a functional group capable of addition polymerization reaction is preferable, a polymerizable ethylenically unsaturated group or a ring polymerizable group is more preferable, acryloyl group, methacryloyl group, vinyl group, Alternatively, a styryl group is more preferable.

The structure of the main chain of Unit 1 is not particularly limited, and known structures may be mentioned, for example, (meth)acrylic skeleton, styrene skeleton, siloxane skeleton, cycloolefin skeleton, methylpentene skeleton, amide A skeleton selected from the group consisting of a system skeleton and an aromatic ester system skeleton is preferable.

Among these, skeletons selected from the group consisting of (meth)acrylic skeletons, siloxane skeletons, and cycloolefin skeletons are more preferable, and (meth)acrylic skeletons are still more preferable.

As unit 1, the repeating unit represented by Formula (1) is preferable at the point which the effect of this invention is more excellent.

[Formula 1]

R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

L ¹ represents a single bond or an n+1 valent linking group. For example, when n is 1, L ¹ represents a divalent linking group, and when n is 2, L ¹ represents a trivalent linking group. In addition, when L ¹ is a single bond, n represents 1.

Examples of the divalent linking group include a divalent aliphatic hydrocarbon group which may have a substituent (eg, an alkylene group), an arylene group which may have a substituent, heteroarylene which may have a substituent, -O- , -CO-, -NH-, or a group combining two or more thereof. As a group combining two or more of these, -CO-O-, -CO-NH-, -O-CO-NH-, a divalent aliphatic hydrocarbon group which may have a -CO-O- substituent-, -CO -NH- The divalent aliphatic hydrocarbon group which may have a substituent -, -NH- The divalent aliphatic hydrocarbon group which may have a substituent -, -CO-O- The divalent aliphatic hydrocarbon group which may have a substituent - Substituent Arylene group which may have -, -CO-O- The divalent aliphatic hydrocarbon group which may have a substituent -O-, -CO-O- The divalent aliphatic hydrocarbon group which may have a substituent -NH-, -CO having a divalent aliphatic hydrocarbon group-O-CO-NH- which may have an -O-substituent, and a divalent aliphatic hydrocarbon group-O-CO-NH-substituent which may have a -CO-O-substituent; The divalent aliphatic hydrocarbon group -O- which may be mentioned is mentioned.

Examples of the trivalent linking group include a trivalent aliphatic hydrocarbon group which may have a substituent, a trivalent aromatic group which may have a substituent, a nitrogen atom (>N-), and a group combining these groups with the above divalent linking group. .

Among them, L ¹ is preferably an n+1 valent linking group containing a hetero atom, more preferably a divalent linking group containing a hetero atom or a trivalent linking group containing a hetero atom, a urethane group, an ester group, and , more preferably a divalent linking group containing at least one selected from the group consisting of amide groups.

As the divalent linking group containing at least one selected from the group consisting of a urethane group, an ester group, and an amide group, at least one selected from the group consisting of a urethane group, an ester group, and an amide group, and an aliphatic hydrocarbon A group combining groups is preferable, and examples thereof include the groups exemplified in "Groups combining two or more of these" described above for the divalent linking group.

P ¹ represents a polymerizable group. The definition of the polymerizable group is as described above.

n represents an integer of 1 or more. Especially, from the point which the effect of this invention is more excellent, as n, 1 or 2 is preferable and 1 is more preferable.

The content of unit 1 in the specific polymerizable polymer is not particularly limited, but from the viewpoint of more excellent effects of the present invention, 20 mass % or more is preferable, and 50 mass % or more is more preferable with respect to all repeating units of the specific polymerizable polymer. It is preferable, and 70 mass % or more is more preferable. Although the upper limit in particular is not restrict|limited, 100 mass % is mentioned, 95 mass % or less in many cases.

Examples of the unit 1 include repeating units shown in Table 1 below.

[Table 1]

The specific polymerizable polymer may contain other repeating units (hereinafter, also referred to as "unit 2") other than the unit 1.

Although the unit 2 in particular is not restrict|limited, From the point which the effect of this invention is more excellent, the repeating unit represented by Formula (2) is mentioned.

[Formula 2]

R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

L ² represents a single bond or a divalent linking group. As a divalent coupling group, the group illustrated as a bivalent coupling group represented by L< ¹ > mentioned above is mentioned.

R ³ represents a hydrocarbon group which may have a substituent. Among these, an aliphatic hydrocarbon group or an aromatic hydrocarbon group (preferably a benzene ring) which may have a substituent is preferable at the point in which the effect of this invention is more excellent.

Although carbon number in particular contained in the said aliphatic hydrocarbon group is not restrict|limited, 1-20 are preferable and 1-10 are more preferable.

The aliphatic hydrocarbon group may be linear or branched. Moreover, the aliphatic hydrocarbon group may have a cyclic structure.

Although the substituent is not particularly limited, for example, an alkyl group, an alkoxy group, an alkyl-substituted alkoxy group, a cyclic alkyl group, an aryl group (eg, a phenyl group, and a naphthyl group), a cyano group, an amino group, a nitro group, an alkyl group A carbonyl group, a sulfo group, and a hydroxyl group are mentioned.

When the specific polymerizable polymer contains other repeating units, the content of unit 2 (for example, the repeating unit represented by the formula (2)) is not particularly limited, but with respect to all repeating units of the specific polymerizable polymer, 80 Mass % or less is preferable, 50 mass % or less is more preferable, 30 mass % or less is still more preferable. Although a minimum in particular is not restrict|limited, 10 mass % or more is mentioned.

Although the weight average molecular weight in particular of a specific polymeric polymer is not restrict|limited, From the point which the effect of this invention is more excellent, 5000 or more are preferable. Although an upper limit in particular is not restrict|limited, 50000 or less are preferable at the point which the effect of this invention is more excellent.

The weight average molecular weight and number average molecular weight in this invention are the values measured by the gel permeation chromatography (GPC) method on the conditions shown below.

Solvent (eluent): THF (tetrahydrofuran)

Device name: TOSOH HLC-8320GPC

·Column: TOSOH TSKgel Super HZM-H (4.6mm×15cm) is used by connecting 3 pieces

·Column temperature: 40℃

・Sample concentration: 0.1% by mass

Flow rate: 1.0ml/min

Calibration curve: A calibration curve with 7 samples from TOSOH made TSK standard polystyrene Mw = 2800000 to 1050 (Mw/Mn = 1.03 to 1.06) is used

As a specific polymeric compound, the compound represented by Formula (3) other than the polymeric compound mentioned above is also preferable.

Formula (3) R ⁴ -L ³ -R ⁵

R ⁴ represents a polymerizable group. The definition of the polymerizable group is as described above.

L ³ represents a single bond or a divalent linking group. As a divalent coupling group, the group illustrated as a bivalent coupling group represented by L< ¹ > mentioned above is mentioned.

R ⁵ represents a boronic acid group or a hydroxyl group.

Although the absolute value of the difference in particular between the SP value of a specific polymeric compound and the SP value of the above-mentioned resin base material is not restrict|limited, From the point which the effect of this invention is more excellent, 2.7 MPa ^1/2 or less is preferable, and 2.0 MPa ^1/2 The following are more preferable. Although a lower limit in particular is not restrict|limited, 0 is mentioned.

(other ingredients)

The optically anisotropic layer may contain components other than the above-described liquid crystal compound and specific compound.

As another component, other components (for example, a chiral agent) which may be contained in the composition used in order to form the optically anisotropic layer mentioned later are mentioned.

Moreover, as mentioned later, the resin which comprises a resin base material may be contained in the optically anisotropic layer. In particular, the resin constituting the resin substrate may be contained in the vicinity of the surface of the optically anisotropic layer on the resin substrate side.

(Requirement 1 and Requirement 2)

The surface of the optical film on the side of the optically anisotropic layer is the first surface, the surface of the optical film on the resin substrate side is the second surface, and the time-of-flight type 2 while irradiating an ion beam from the first surface to the second surface side When the component in the depth direction of an optical film is analyzed by differential ion mass spectrometry, the optical film of this invention satisfy|fills both the following requirement 1 and requirement 2.

Requirement 1: The depth position located on the second most surface side showing the secondary ionic strength that is 80% of the maximum strength of the secondary ionic strength derived from the liquid crystal compound is the position A, and 2 derived from the resin constituting the resin substrate When the depth position located on the first surface side showing the secondary ionic strength that is 80% of the maximum intensity of the primary ionic strength is set to the B position, in any one of the depth positions between the A position and the B position, The maximum value Imax of the secondary ionic strength derived from the compound having a hetero atom is shown.

Requirement 2: The depth position showing the maximum value Imax of the secondary ionic strength derived from the compound having a hetero atom is the peak position, and the peak position is on the first surface side from the peak position showing the secondary ionic strength of the maximum value Imax, the most peak position When the depth position closest to is the position C, the second surface side from the peak position showing the secondary ionic strength half of the maximum value Imax, and the depth position closest to the peak position is the position D, the C position and D The distance between the positions is 100 nm or less.

Hereinafter, the above requirements will be described in detail with reference to the drawings. In addition, in the drawings shown below, the scale etc. differ from actual data so that the content of invention may be easily understood.

An example of the profile obtained by analyzing the components in the depth direction in each layer by TOF-SIMS while performing ion sputtering from the first surface 10A to the second surface 10B of the optically anisotropic layer of FIG. 1 is shown in FIG. 2 .

In addition, in this specification, the depth direction intends the direction toward the 2nd surface on the basis of the 1st surface of an optically anisotropic layer.

As shown in FIG. 1 , the surface of the optical film 10 on the side of the optically anisotropic layer 14 is the first surface 10A, and the surface of the optical film 10 on the side of the resin substrate 12 is the second surface. (10B).

In the profile in the depth direction described in FIG. 2 , the horizontal axis (in FIG. 2 , the axis extending in the left and right directions of the paper sheet) indicates the depth with respect to the first surface, and the vertical axis (in FIG. 2 , the vertical direction of the paper sheet is extending axis) represents the secondary ionic strength of each component.

In addition, the TOF-SIMS method is specifically described in the Japanese Society of Surface Sciences edition "Secondary Ion Mass Spectrometry for Surface Analysis Technology" (published in 1999) by Maruzen Corporation.

In addition, when analyzing the component in the depth direction of the optical film by TOF-SIMS while irradiating the ion beam, after performing the component analysis in the surface depth region of 1 to 2 nm, the parsing proceeds in the depth direction by 1 nm to several hundred nm, and the following A series of operations for performing component analysis of a surface depth region of 1 to 2 nm is repeated.

In the profile in the depth direction shown in FIG. 2, the result of secondary ionic strength derived from the liquid crystal compound (C1 in the figure), the result of secondary ionic strength derived from the resin constituting the resin substrate (C2 in the figure), and specific The result of secondary ionic strength derived from the compound (C3 in the figure) is shown.

In addition, in this specification, "secondary ionic strength derived from a liquid crystal compound" obtained by the profile in the depth direction detected by analyzing the components in the depth direction of the optical film by TOF-SIMS refers to the fragment ions derived from the liquid crystal compound. The strength is intended, "resin-derived secondary ionic strength" means the strength of fragment ions derived from the resin constituting the resin substrate, and "secondary ionic strength derived from a specific compound" means that The intensity of fragment ions is intended.

As shown in FIG. 2, TOF-SIMS method, irradiating an ion beam from the 1st surface 10A side of the optical film 10 toward the 2nd surface 10B side (toward the direction of the white arrow in FIG. 1) When the component in the depth direction of the optical film 10 is analyzed by using The secondary ionic strength of is gradually lowered. This means that the resin substrate 12 is approaching from the optically anisotropic layer 14 . If the component in the depth direction is analyzed while irradiating the ion beam further toward the depth direction, the resin substrate 12 will be reached, and the secondary ion intensity derived from the liquid crystal compound will not be observed.

Moreover, as shown in FIG. 2, when a component is analyzed from the 1st surface 10A side toward the 2nd surface 10B side, the secondary ionic strength derived from the resin which comprises the resin base material 12 is 2nd It increases as it goes toward the surface 10B side. Moreover, when a component is analyzed toward the depth direction, it will reach|attain the resin base material 12, and the secondary ionic strength derived from resin which comprises the resin base material 12 will become the highest.

In FIG. 2, the result of the secondary ionic strength derived from a specific compound (C3 in a figure) is shown. As shown in FIG. 2, the secondary ion derived from a specific compound is strongly observed mainly in the area|region where both the secondary ion derived from a liquid crystal compound and the secondary ion derived from resin are observed.

More specifically, first, in the profile in the depth direction shown in Fig. 2, the depth position located on the second most surface side showing the secondary ionic strength that is 80% of the maximum intensity of the secondary ionic strength derived from the liquid crystal compound. Let be position A, and the depth position located on the most first surface side showing secondary ionic strength that is 80% of the maximum strength of secondary ionic strength derived from resin constituting the resin substrate is position B.

In FIG. 2 , the maximum intensity of the secondary ionic strength derived from the liquid crystal compound corresponds to M1, and the depth position (the second surface most A position close to ) is referred to as position A. Therefore, for example, when there exist two or more depth positions which show the secondary ionic strength of 80% of M1, let the depth position located most 2nd surface side be the A position.

In addition, in FIG. 2, since the maximum intensity of the secondary ionic strength derived from the resin corresponds to M2, the depth position (closest to the first surface) located on the first surface side showing the strength of 80% of M2 position) as position B. Therefore, for example, when there exist two or more depth positions which show the secondary ionic strength of 80% of M2, let the depth position located most 1st surface side be the B position.

In addition, in the vicinity of the first surface and in the vicinity of the second surface, noise due to foreign matter may occur, so a region between 50 nm from the first surface to the second surface side (hereinafter also referred to as a first surface region). ), and the secondary ionic strength of each component in the region between 50 nm from the second surface toward the first surface side (hereinafter also referred to as a second surface region) is the maximum intensity described above. It is not taken into account when calculating. More specifically, the maximum intensity of the secondary ionic strength derived from the liquid crystal compound is a liquid crystal in a region excluding the first surface region and the second surface region in the obtained secondary ionic strength profile derived from the liquid crystal compound. The maximum intensity among secondary ionic strengths derived from the compound is calculated as the maximum intensity. In addition, the maximum intensity of the secondary ionic strength derived from the resin is a secondary ion derived from the resin in the region excluding the first surface region and the second surface region in the obtained resin-derived secondary ionic strength profile. The maximum intensity among the intensity|strengths is computed as a maximum intensity|strength.

In the requirement 1, the maximum value Imax of the secondary ionic strength derived from a specific compound is shown in any one depth position between A position and B position specified above. In FIG. 2, the maximum value Imax is shown in the peak position PP. That is, between the A position and the B position, the maximum value Imax of the secondary ionic strength derived from the specific compound is observed.

In the optical film satisfying the requirement 1, the specific compound is unevenly distributed on the resin substrate side in the optically anisotropic layer. By satisfying such requirement 1, the adhesiveness between a resin base material and an optically anisotropic layer becomes favorable.

Moreover, as shown in FIG. 2, in an optical film, it is preferable that the peak which shows the maximum value Imax is observed in the peak position PP located between A position and B position.

Moreover, as shown in FIG. 2, it is on the 1st surface side from the peak position, which shows the secondary ionic strength (Imax/2) of half of the maximum value Imax, let the depth position closest to the peak position be the C position, and the maximum value When the depth position closest to the peak position is on the second surface side from the peak position, indicating the secondary ionic strength (Imax/2) of half of Imax, the position C and the position D indicated by white arrows are The distance between them (hereinafter also referred to as Iwid) is 100 nm or less.

In the optical film which satisfies the requirement 2, the quantity of the specific compound which is localized is a predetermined amount or less. That is, when the amount of a specific compound that is localized is too large, the Iwid becomes greater than 100 nm. By satisfying such requirement 2, the orientation of the liquid crystal compound in the optically anisotropic layer is improved, and the occurrence of optical defects in the optically anisotropic layer is suppressed. When the requirement 2 is not satisfied, since the amount of the specific compound is too large, the orientation regulating force of the resin substrate is weakened, resulting in deterioration of the orientation of the liquid crystal compound.

Among them, the Iwid is preferably 50 nm or less from the viewpoint of further suppressing the occurrence of optical defects in the optically anisotropic layer. Although a lower limit in particular is not restrict|limited, There are many cases of 1 nm or more, and there are more cases of 5 micrometers or more.

Among them, since the effect of the present invention is more excellent, when the average intensity of secondary ionic strength derived from a specific compound from the first surface to the A position is taken as the average value Iave, the maximum value Imax and the average value Iave are the ), it is desirable to satisfy the relationship of

Equation (A) 1.3≤Imax/Iave

Especially, 50 or more are preferable and, as for Imax/Iave, 100 or more are more preferable at the point which the effect of this invention is more excellent. Although an upper limit in particular is not restrict|limited, Imax/Iave has many cases of 1000 or less, and there are more cases of 500 or less.

However, in the vicinity of the first surface, noise due to foreign matter may be generated, so that in the region between 50 nm from the first surface to the second surface side (first surface region), the specific compound-derived The secondary ionic strength is not taken into account when calculating Iave described above. More specifically, Iave is the secondary ionic strength profile derived from the specific compound obtained, in the region from the first surface to the A position, in the region excluding the first surface region, secondary derived from the specific compound Let it be the average intensity|strength of ionic strength.

<Production method>

Although the manufacturing method of the optical film of this invention is not specifically limited, From the point which can manufacture an optical film with good productivity, a polymeric liquid crystal compound, and a composition containing a specific polymeric compound (hereinafter, simply "specific composition") Also called.) is preferred. More specifically, a specific composition is applied on a resin substrate having an orientation regulating force to form a composition layer, the polymerizable liquid crystal compound in the composition layer is oriented, and then the alignment state of the polymerizable liquid crystal compound is fixed, and the resin A method for producing an optical film having a substrate and an optically anisotropic layer formed on a resin substrate is preferred.

Hereinafter, the procedure of the above method will be described in detail.

The resin base material which has an orientation regulating force used in the said manufacturing method is as above-mentioned.

The polymerizable liquid crystal compound contained in the specific composition and the specific polymerizable compound (preferably, specific polymerizable polymer) are as described above.

Although content in particular of the polymeric liquid crystal compound in a specific composition is not restrict|limited, 50 mass % or more is preferable with respect to the total solid in a specific composition, and 70 mass % or more is more preferable. Although the upper limit in particular is not restrict|limited, 90 mass % or less in many cases.

10 mass % or less is preferable with respect to the total mass of a polymeric liquid crystal compound, as for content of the specific polymeric compound in a specific composition, 5 mass % or less is more preferable, and its 2 mass % or less is more preferable. Although a lower limit in particular is not restrict|limited, 0.1 mass % or more is preferable, and 0.3 mass % or more is more preferable.

In addition, solid content means the component which can form the optically anisotropic layer from which the solvent in a specific composition was removed, and even if the property is liquid, let it be solid.

The specific composition may contain other components other than the above-mentioned polymeric liquid crystal compound and a specific polymeric compound.

For example, the specific composition may contain the solvent.

Examples of the solvent include ester solvents, ether solvents, amide solvents, carbonate solvents, ketone solvents, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated carbons. solvents, water, and alcohol solvents. Among them, an ester-based solvent, an ether-based solvent, an amide-based solvent, a carbonate-based solvent, or a ketone-based solvent is preferable.

Moreover, only 1 type may be used for a solvent, and 2 or more types may be mixed and used for it.

The specific composition may contain the polymerization initiator. When the specific composition contains a polymerization initiator, polymerization of the polymerizable liquid crystal compound proceeds more efficiently.

As a polymerization initiator, a well-known polymerization initiator is mentioned, A photoinitiator and a thermal polymerization initiator are mentioned, A photoinitiator is preferable.

Although content in particular of the polymerization initiator in a specific composition is not restrict|limited, 0.01-20 mass % is preferable with respect to the total solid in a specific composition, and 0.5-10 mass % is more preferable.

The specific composition may contain surfactant. Although a conventionally well-known compound is mentioned as surfactant, A fluorine-type compound is preferable. Specifically, the compound of Paragraph 0028 - 0056 in Unexamined-Japanese-Patent No. 2001-330725, and the compound of Paragraph 0069 - 0126 in Unexamined-Japanese-Patent No. 2005-062673 are mentioned, for example.

The specific composition may contain the polymer. Examples of the polymer include cellulose esters. As a cellulose ester, the thing of Paragraph 0178 in Unexamined-Japanese-Patent No. 2000-155216 is mentioned.

Although content in particular of the polymer in a specific composition is not restrict|limited, 0.1-10 mass % is preferable with respect to the polymeric liquid crystal compound total mass, and 0.1-8 mass % is more preferable.

The specific composition may contain the additive (orientation control agent) which accelerates|stimulates horizontal alignment or vertical alignment, in order to make a polymeric liquid crystal compound into a horizontal alignment state or a vertical alignment state.

The specific composition may further contain a chiral agent. When the specific composition contains the chiral agent, the polymerizable liquid crystal compound can be twisted along the helical axis.

The kind in particular of a chiral agent is not restrict|limited. Any of the known chiral agents (for example, "Liquid Crystal Device Handbook," Chapter 3, Paragraph 4-3, Chiral Agents for TN and STN, page 199, described in 1989 by the 142nd Committee of the Japan Association for the Promotion of Science and Technology) Available.

In addition, the helical organic force (HTP) of a chiral agent is a factor which shows the helical orientation ability represented by following formula (X).

Formula (X) HTP=1/(length of helix pitch (unit: μm) × concentration of chiral agent in liquid crystal compound (mass %)) [μm ^-1 ]

The length of the helical pitch means the length of the pitch P (= helix period) of the helical structure of the cholesteric liquid crystal phase, and can be measured by the method described on page 196 of the liquid crystal handbook (Maruzen Co., Ltd. publication).

The chiral agent may be a photosensitive chiral agent whose spiral organic force is changed by irradiation with light (hereinafter also simply referred to as "chiral agent A"). The chiral agent A may be liquid crystalline or non-liquid crystalline may be sufficient as it. The chiral agent A generally contains an asymmetric carbon atom in many cases. In addition, the chiral agent A may be an asymmetric asymmetric compound or a planar asymmetric compound which does not contain an asymmetric carbon atom.

The chiral agent A may have a polymerizable group.

The chiral agent A may be a chiral agent whose spiral organic force increases by irradiation with light, or may be a chiral agent that decreases. Especially, it is preferable that it is a chiral agent whose spiral organic force decreases by light irradiation.

In addition, in this specification, "increase and decrease in helical induction force" represents an increase or decrease when the helical direction of the initial stage (before light irradiation) of the chiral agent A is defined as "positive". Therefore, when the helical induced force continues to decrease due to light irradiation, and the helical direction becomes "negative" when it exceeds 0 (that is, the helical direction opposite to the initial (before light irradiation) helical direction is induced. case), it corresponds to "a chiral agent with reduced spiral organic force".

Examples of the chiral agent A include so-called photoreactive chiral agents. The photoreactive chiral agent is a compound that has a chiral moiety and a photoreactive moiety that changes its structure upon irradiation with light, for example, greatly changing the torsional force of a liquid crystal compound depending on the amount of irradiation.

Among them, as the chiral agent A, a compound having at least a photoisomerization moiety is preferable, and a photoisomerization moiety having a double bond capable of being photoisomerized is more preferable. As the photoisomerization moiety having a double bond capable of photoisomerization, a cinnamoyl moiety, a chalcone moiety, an azobenzene moiety or a stilbene moiety is preferable from the viewpoint of easy photoisomerization and a large difference in helical organic dynamics before and after light irradiation, Moreover, since absorption of visible light is small, a cinnamoyl moiety, a chalcone moiety, or a stilbene moiety is more preferable. In addition, the photoisomerization site|part corresponds to the photoreactive site|part whose structure changes by the light irradiation mentioned above.

In addition, the chiral agent A is selected from a binaphthyl partial structure, an isosorbide partial structure (a partial structure derived from isosorbide), and an isomannide partial structure (a partial structure derived from isomannide) It is preferable to have any one partial structure. In addition, the following structures are intended with a binaphthyl partial structure, a child carbide partial structure, and an isomannide partial structure, respectively.

A portion in the binaphthyl partial structure in which the solid line and the broken line are parallel to each other indicates a single bond or a double bond. In addition, in the structure shown below, * represents a bonding position.

[Formula 3]

The specific composition may contain two or more types of chiral agent A, and at least one type of chiral agent A and at least one type of light irradiation of a chiral agent whose helical organic force does not change (hereinafter simply referred to as "ca It is also referred to as "Iralze B".) may be included.

The chiral agent B may be liquid crystalline or non-liquid crystalline. The chiral agent B generally contains an asymmetric carbon atom in many cases. In addition, the chiral agent B may be an asymmetric asymmetric compound or a planar asymmetric compound which does not contain an asymmetric carbon atom.

The chiral agent B may have a polymerizable group.

As the chiral agent B, a known chiral agent can be used.

The chiral agent B is preferably a chiral agent that induces a helix in the opposite direction to that of the above-described chiral agent A. That is, for example, when the helix induced by the chiral agent A is in the right direction, the helix induced by the chiral agent B is in the left direction.

The absolute value of the weighted average helical inductive force of the chiral agent is preferably 0.0 to 1.9 μm ^-1 , more preferably 0.0 to 1.5 μm ^-1 , still more preferably 0.0 to 1.0 μm ^-1 , 0.0 to 0.5 μm ⁻¹ is particularly preferred, and zero is most preferred.

When the absolute value of the weighted average helical organic force of the chiral agent is within the above range, an optically anisotropic layer having two or more layers having different optical properties along the thickness direction depending on the manufacturing conditions of the optically anisotropic layer, as will be described later. easy to form

In addition, the weighted average helical organic force of a chiral agent is, when two or more types of chiral agents are included in a specific composition, the helical organic force of each chiral agent and the concentration (mass) of each chiral agent with respect to the polymerizable liquid crystal compound %) divided by the total concentration (mass %) of the chiral agent to the polymerizable liquid crystal compound is shown. For example, when two types of chiral agents (chiral agent X and chiral agent Y) are used together, it is represented by the following formula (Y).

Formula (Y) weighted average helical organic force (μm ^-1 ) = (helical organic force of chiral agent X (μm ^-1 ) x concentration of chiral agent X with respect to the polymerizable liquid crystal compound (mass %) + chiral agent Spiral organic force of Y (μm ^-1 ) x concentration of chiral agent Y in the polymerizable liquid crystal compound (mass %))/(concentration of chiral agent X in the polymerizable liquid crystal compound (mass %) + polymerizable liquid crystal Concentration of chiral agent Y to compound (% by mass)

However, in the said Formula (Y), when the helical direction of a chiral agent is a right winding, let the helical induced force be a positive value. In addition, when the spiral direction of a chiral agent is a left winding, the spiral induction force is made into a negative value. That is, for example, in the case of a chiral agent having a helical induction force of 10 μm ⁻¹ , when the helical direction of a helix induced by the chiral agent is a right winding, the helical induction force is expressed as 10 μm ⁻¹ . On the other hand, when the helical direction of the helix induced by the chiral agent is a left winding, the helical induced force is expressed as -10 µm ^-1 .

Although content in particular of the said chiral agent A in a specific composition is not restrict|limited, From the point which a polymeric liquid crystal compound is easy to orientate uniformly, 5.0 mass % or less is preferable with respect to the total mass of a polymeric liquid crystal compound, and 3.0 Mass % or less is more preferable, and 2.0 mass % or less is still more preferable. Although a minimum in particular is not restrict|limited, 0.01 mass % or more is preferable, and 0.02 mass % or more is more preferable.

In addition, the said chiral agent A may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types of said chiral agent A together, it is preferable that total content exists in the said range.

Although content in particular of the said chiral agent B in a specific composition is not restrict|limited, From the point which a polymeric liquid crystal compound is easy to orientate uniformly, 5.0 mass % or less is preferable with respect to the total mass of a polymeric liquid crystal compound, and 3.0 Mass % or less is more preferable, and 2.0 mass % or less is still more preferable. Although a minimum in particular is not restrict|limited, 0.01 mass % or more is preferable, and 0.02 mass % or more is more preferable.

In addition, the said chiral agent B may be used individually by 1 type, and may use 2 or more types together. When using together 2 or more types of said chiral agent B, it is preferable that total content exists in the said range.

5.0 mass % or less is preferable with respect to the total mass of a polymeric liquid crystal compound, as for the total content of a chiral agent in a specific composition (total content of all chiral agents), 4.0 mass % or less is more preferable, 2.0 mass % or less % by mass or less is more preferable. Although a minimum in particular is not restrict|limited, 0.01 mass % or more is preferable, and 0.02 mass % or more is more preferable.

(Sequence)

When manufacturing an optical film, a specific composition is apply|coated on a resin base material, and a composition layer is formed. Certain compositions are applied directly onto a resin substrate. In other words, the specific composition is applied so that the surface of the resin substrate and the specific composition are in contact.

The coating method is not particularly limited, and examples thereof include a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method.

Moreover, you may perform the process of drying the composition layer apply|coated on the resin base material after application|coating of a specific composition as needed. By performing a drying process, a solvent can be removed from a composition layer.

Although the film thickness in particular of a composition layer is not restrict|limited, 0.1-20 micrometers is preferable, 0.2-15 micrometers is more preferable, 0.5-10 micrometers is still more preferable.

Next, the polymerizable liquid crystal compound in the composition layer is aligned.

Although the process in particular for orientating a polymeric liquid crystal compound is not restrict|limited, Heat processing is preferable.

As conditions for the heat treatment, optimal conditions are selected according to the polymerizable liquid crystal compound to be used.

Especially, as heating temperature, there are many cases of 10-250 degreeC, there are many cases of 40-150 degreeC, and there are many cases of 50-130 degreeC.

As heating time, there are many cases for 0.1 to 60 minutes, and there are more cases for 0.2 to 5 minutes.

The orientation state of a polymeric liquid crystal compound changes with the material in a composition layer. As an orientation state, homogeneous orientation is mentioned, for example. Moreover, when a chiral agent is contained in a composition layer, a polymeric liquid crystal compound torsion-aligns along the helical axis extending along the thickness direction of a composition layer.

Next, the alignment state of the polymerizable liquid crystal compound is fixed to form an optically anisotropic layer.

The method in particular of fixing an orientation state is not restrict|limited, The method of hardening processing with respect to a composition layer, making the polymeric group in a polymeric liquid crystal compound react, and forming an optically anisotropic layer (hardened layer) is mentioned.

The method in particular of a hardening process is not restrict|limited, A photocuring process and a thermosetting process are mentioned. Among them, light irradiation treatment is preferable, and ultraviolet irradiation treatment is more preferred.

Light sources, such as an ultraviolet lamp, are used for ultraviolet irradiation.

Although the irradiation amount in particular of light (for example, ultraviolet-ray) is not restrict|limited, Generally, about 100-800 mJ/cm< ² > is preferable.

In the optically anisotropic layer obtained by performing a hardening process, the orientation state of a polymeric liquid crystal compound is fixed.

For example, as an optically anisotropic layer, the layer formed by fixing the polymeric liquid crystal compound which carried out the homogeneous orientation is mentioned. Moreover, as an optically anisotropic layer, the layer formed by fixing the polymeric liquid crystal compound which carried out the twist orientation which makes the thickness direction a helical axis is also mentioned.

In addition, the "fixed" state means a state in which the alignment of the liquid crystal compound is maintained. It is not limited thereto, and specifically, there is no fluidity in the layer in the temperature range of 0 to 50° C., and -30 to 70° C. under more severe conditions, and the orientation changes due to external or external force. It is preferable to be in a state in which a fixed orientation form can be stably maintained without generating .

In addition, in the optically anisotropic layer, finally, the composition in the layer does not need to exhibit liquid crystallinity any longer.

The optically anisotropic layer may have a single layer structure or a multilayer structure. The multilayer structure means a structure in which two or more layers having different optical properties are laminated.

For example, when a specific composition contains the chiral agent A, the optically anisotropic layer which has two layers from which an optical characteristic differs by one application process by implementing the following process A - process E can be manufactured.

Step A: A step of forming a composition layer by applying a specific composition containing the chiral agent A on a resin substrate

Step B: A step of heat-treating the composition layer to orient the polymerizable liquid crystal compound in the composition layer

Step C: After Step B, a step of irradiating the composition layer with light under the condition of an oxygen concentration of 1% by volume or more

Step D: Step of subjecting the composition layer to heat treatment after step C

Step E: After Step D, a step of curing the composition layer, fixing the orientation state of the polymerizable liquid crystal compound, and forming an optically anisotropic layer

Hereinafter, the procedure of each said process is demonstrated in detail.

(Process A)

As a procedure of process A, the above-mentioned procedure of apply|coating a specific composition is mentioned.

In addition, the specific composition used in process A contains the chiral agent A in addition to the above-mentioned polymeric liquid crystal compound and a specific polymeric compound. As will be described later, the specific composition may contain the chiral agent B.

(Process B)

Although the procedure in particular of process B is not restrict|limited, The method of orientating the above-mentioned polymeric liquid crystal compound is mentioned.

(Process C)

Process C is demonstrated using drawings below.

In the following description, two types of chiral agents, chiral agent A and chiral agent B, are included in a specific composition, and the absolute value of the weighted average helical organic force of the chiral agent in the composition layer formed by step A is 0 The case will be described representatively.

As shown in FIG. 3, the composition layer 16 in which the polymeric liquid crystal compound (LC) carried out the homogeneous orientation is formed on the resin base material 12 by process B. In addition, FIG. 3 is a schematic diagram of the cross section of the resin base material 12 and the composition layer 16. As shown in FIG. In addition, in the composition layer 16 shown in Fig. 3, the chiral agent A and the chiral agent B are present at the same concentration, and the helical direction induced by the chiral agent A is left-winding, and by the chiral agent B The induced spiral direction is called right winding. In addition, the absolute value of the helical induction force of the chiral agent A and the absolute value of the helical induction force of the chiral agent B are made the same.

As shown in FIG. 4 , in the above-described step C, light is emitted from the direction opposite to the composition layer 16 side of the resin substrate 12 (the direction of the white arrow in FIG. 4 ) under the condition of an oxygen concentration of 1% by volume or more. conduct an investigation In addition, although light irradiation is implemented from the resin base material 12 side in FIG. 4, you may implement from the composition layer 16 side.

At that time, when the lower region 16A on the side of the resin substrate 12 of the composition layer 16 is compared with the upper region 16B on the opposite side to the resin substrate 12 side, the surface side of the upper region 16B is Since it is on the air side, the oxygen concentration in the upper region 16B is high and the oxygen concentration in the lower region 16A is low. Therefore, when light irradiation is made to the composition layer 16, polymerization of the polymerizable liquid crystal compound tends to proceed in the lower region 16A, and the alignment state of the polymerizable liquid crystal compound is fixed. Further, the chiral agent A is present also in the lower region 16A, and the chiral agent A is also photosensitized to change the helical induced force. However, since the alignment state of the polymerizable liquid crystal compound is fixed in the lower region 16A, the change in the alignment state of the liquid crystal compound will be doesn't happen

Moreover, in the upper region 16B, since the oxygen concentration is high, even when light irradiation is made, the polymerization of the polymerizable liquid crystal compound is inhibited by oxygen and the polymerization is difficult to proceed. And since the chiral agent A exists also in the upper area|region 16B, the chiral agent A is photosensitive, and the spiral organic force changes. Therefore, when the process D (heating process) mentioned later is implemented, the orientation state of a polymeric liquid crystal compound will change according to the changed spiral organic force.

That is, by implementing the process C, in the area|region (lower area|region) by the side of the resin base material of a composition layer, fixation of the orientation state of a polymeric liquid crystal compound advances easily. In addition, in the region (upper region) opposite to the resin substrate side of the composition layer, solidification of the alignment state of the polymerizable liquid crystal compound does not proceed easily, and the state in which the helical organic force is changed according to the photosensitized chiral agent A. do.

Step C is carried out under the conditions of an oxygen concentration of 1% by volume or more. Among them, in the optically anisotropic layer, layers having different orientation states of the polymerizable liquid crystal compound are easily formed, so that the oxygen concentration is preferably 2% by volume or more, and more preferably 5% by volume or more. Although the upper limit in particular is not restrict|limited, 100 volume% is mentioned.

The irradiation intensity in particular of the light irradiation in process C is not restrict|limited, Based on the spiral organic force of the chiral agent A, it can determine suitably. Although the irradiation amount in particular of the light irradiation in process C is not restrict|limited, From the point which a predetermined optically anisotropic layer is easy to form, 300 mJ/cm< ² > or less is preferable, and 200 mJ/cm< ² > or less is more preferable. As a lower limit, 10 mJ/cm ² or more is preferable, and 30 mJ/cm ² or more is more preferable from the point where a predetermined optically anisotropic layer is easy to form.

Moreover, it is preferable that light irradiation in process C is implemented at 15-70 degreeC (preferably 15-50 degreeC).

The light used for light irradiation should just be the light which the chiral agent A photosensitizes. That is, the light used for light irradiation is not particularly limited as long as it is actinic ray or radiation that changes the helical organic force of the chiral agent A. For example, the bright spectrum of a mercury lamp, far ultraviolet ray represented by excimer laser, extreme ultraviolet ray , X-rays, ultraviolet rays, and electron beams. Among them, ultraviolet rays are preferable.

(Process D)

Step D is a step of heat-treating the composition layer after step C. By implementing this process, the orientation state of a liquid crystal compound changes in the area|region where the helical organic force of the chiral agent A in the composition layer to which the light irradiation was given changed.

Hereinafter, the mechanism of this process is demonstrated using drawings.

As described above, when step C is performed on the composition layer 16 shown in FIG. 3 , as shown in FIG. 4 , the alignment state of the polymerizable liquid crystal compound is fixed in the lower region 16A in the upper region In (16B), the polymerization of the polymerizable liquid crystal compound hardly proceeds, and the alignment state of the polymerizable liquid crystal compound is not fixed. In addition, in the upper region 16B, the helical induction force of the chiral agent A is changing. When such a change in the helical induced force of the chiral agent A occurs, the force to twist the polymerizable liquid crystal compound in the upper region 16B is changed compared with the state before light irradiation. This point will be described in more detail.

As described above, in the composition layer 16 shown in FIG. 3 , the chiral agent A and the chiral agent B are present at the same concentration, and the helical direction induced by the chiral agent A is left-winding, and the chiral agent The spiral direction induced by B is the right winding. Moreover, the absolute value of the helical induction force of the chiral agent A and the absolute value of the helical induction force of the chiral agent B are the same. Therefore, the weighted average helical organic force of the chiral agent in the composition layer before light irradiation is zero.

The above aspect is shown in FIG. In Fig. 5 , the vertical axis represents "helical inductive force (μm ^-1 ) of chiral agent x concentration (mass %) of chiral agent", and as the value moves away from zero, the helical inductive force increases. The horizontal axis represents "light irradiation dose (mJ/cm ² )".

First, the relationship between the chiral agent A and the chiral agent B in the composition layer before light irradiation corresponds to the point in time when the amount of light irradiation is 0, and "spiral organic force of chiral agent A (μm ^-1 ) x ka The absolute value of "concentration (mass %) of chiral agent A" corresponds to a state in which the absolute value of "helical organic force of chiral agent B (μm ^-1 ) x concentration of chiral agent B (mass %)" is the same. That is, the helical force of both the chiral agent A that induces the left winding and the chiral agent B that induces the right winding is offset.

When light is irradiated in the upper region 16B in such a state, and as shown in FIG. 5 , when the helical inducer force of the chiral agent A decreases depending on the light irradiation amount, as shown in FIG. 6 , the upper region ( The weighted average helical induced force of the chiral agent in 16B) becomes large, and the helical induced force of the right winding becomes strong. That is, as for the helical induced force for inducing the helical of the polymerizable liquid crystal compound, the greater the irradiated amount, the greater the helical induced force in the direction (+) of the helical induced by the chiral agent B.

Therefore, when the composition layer 16 after the step C in which such a change in the weighted average helical force has occurred is subjected to heat treatment to promote re-orientation of the liquid crystal compound, as shown in FIG. 4 , the upper region In (16B), the polymerizable liquid crystal compound (LC) is torsionally aligned along the helical axis extending along the thickness direction of the composition layer 16 .

On the other hand, as described above, in the lower region 16A of the composition layer 16, polymerization of the polymerizable liquid crystal compound proceeds during step C and the alignment state of the polymerizable liquid crystal compound is fixed, so the polymerizable liquid crystal compound reorientation does not proceed.

As mentioned above, by implementing process D, two or more areas|regions from which the orientation state of a polymeric liquid crystal compound differs along the thickness direction of a composition layer are formed.

The degree of twist of the polymerizable liquid crystal compound (LC) can be appropriately adjusted depending on the type of the chiral agent A used, the exposure amount in the step C, and the like.

In addition, in the said FIGS. 3 and 4, although the aspect using the chiral agent in which the spiral organic force decreases by light irradiation as chiral agent A was demonstrated, it is not limited to this aspect. For example, as the chiral agent A, a chiral agent whose helical organic force increases by irradiation with light may be used. In that case, the helical organic force induced by the chiral agent A is increased by irradiation with light, and the liquid crystal compound is torsionally oriented in the turning direction induced by the chiral agent A.

In addition, in the said FIGS. 3 and 4, although the aspect which uses the chiral agent A and the chiral agent B together was demonstrated, it is not limited to this aspect. For example, the aspect using two types of chiral agent A may be sufficient. Specifically, the aspect of using together the chiral agent A1 which induces a left winding, and the chiral agent A2 which induces a right winding may be sufficient. The chiral agents A1 and A2 may each independently be a chiral agent with an increased helical organic force or a chiral agent with a reduced helical organic force. For example, it is a chiral agent that induces left winding, a chiral agent that increases helical induced force by light irradiation, and a chiral agent that induces right winding, and a chiral agent whose helical induced force decreases by light irradiation. You may use iral agent together.

As conditions for heat treatment, optimal conditions are selected according to the liquid crystal compound used.

Among them, the heating temperature is preferably a temperature heated from the process C state, in many cases of 35 to 250 ° C, more often in the range of 50 to 150 ° C, and in more cases of more than 50 ° C and less than or equal to 150 ° C, 60 It is especially common at ~130°C.

As heating time, there are many cases for 0.01 to 60 minutes, and there are more cases for 0.03 to 5 minutes.

In addition, the absolute value of the weighted average helical induced force of the chiral agent in the composition layer after light irradiation is not particularly limited, 0.05 micrometer ^-1 or more is preferable, as for the absolute value of a difference, 0.05-10.0 micrometers ^-1 are more preferable, 0.1-10.0 micrometers ^-1 are still more preferable.

(Process E)

Although the procedure in particular of process E is not restrict|limited, The hardening process mentioned above is mentioned.

When the curing treatment is performed on the composition layer shown in Fig. 7, the optically anisotropic layer formed is a layer formed by fixing the alignment state of the polymeric liquid crystal compound in homogeneous alignment from the resin substrate side, and extending along the thickness direction. and two layers of layers formed by fixing the alignment state of the polymerizable liquid crystal compound twisted along the helical axis. That is, the optically anisotropic layer to be formed has a multilayer structure.

<Optical Film>

The obtained optical film can be applied to various uses, For example, the optical compensation film for optically compensating a liquid crystal cell, and the antireflection film used for display apparatuses, such as an organic electroluminescent display apparatus, is mentioned. .

<Circular Polarizer>

The above-described optical film may be used as a circularly polarizing plate in combination with a polarizer.

The polarizer may be a member having a function of converting natural light into specific linearly polarized light, and examples thereof include an absorption type polarizer.

There is no restriction|limiting in particular in the kind of polarizer, A polarizer normally used can be used, For example, an iodine type polarizer, the dye type polarizer using a dichroic dye, and a polyene type polarizer are mentioned. Generally, an iodine type polarizer and a dye type polarizer make iodine or a dichroic dye adsorb|suck to polyvinyl alcohol, and are produced by extending|stretching.

In addition, a protective film may be arrange|positioned on the single side|surface or both surfaces of a polarizer.

The manufacturing method in particular of a circularly polarizing plate is not restrict|limited, A well-known method is employable.

For example, the method of bonding an optical film and a polarizer together through an adhesion layer is mentioned.

The said circularly-polarizing plate is applicable suitably as an antireflection film of an organic electroluminescent display.

Example

Hereinafter, the features of the present invention will be described in more detail with reference to Examples and Comparative Examples. Materials, usage amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Example 1>

(Preparation of cellulose acylate film (substrate))

The following components are put into a mixing tank, stirred, and heated at 90° C. for 10 minutes, then filtered through a filter paper having an average pore diameter of 34 μm and a sintered metal filter having an average pore diameter of 10 μm, and cellulose acylate dope (hereinafter simply “doped”). Also referred to as "). The solid content concentration of the obtained dope was 23.5 mass %, and the mass ratio of the solvent was methylene chloride/methanol/butanol =81/18/1.

------------------------------------------------------------ -----------

Cellulose acylate dope

------------------------------------------------------------ -----------

100 parts by mass of cellulose acylate (acetyl substitution degree 2.86, viscosity average degree of polymerization 310)

Sugar ester compound 1 (represented by the general formula (S4)) 6.0 parts by mass

Sugar ester compound 2 (represented by the general formula (S5)) 2.0 parts by mass

Silica particle dispersion (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 parts by mass

Solvent (methylene chloride/methanol/butanol) predetermined amount

------------------------------------------------------------ -----------

[Formula 4]

[Formula 5]

Dope mentioned above was cast|flow_spreaded using the drum film making machine. The dope for forming the core layer and the dope for forming the surface layer on the core layer were co-cast from the die so as to be in contact with the metal substrate cooled to 0°C, and then the obtained film was peeled off. In addition, the drum was made of SUS (Steel Use Stainless).

The film peeled from the drum was dried at 30-40 degreeC for 20 minutes at the time of conveyance using the tenter apparatus which clips and conveys the both ends of a film with a clip. Next, it post-dried by zone heating, roll conveying the obtained film. Then, after knurling to the obtained film, it wound up.

The obtained elongate cellulose acylate film had a film thickness of 40 µm, an in-plane retardation Re (550) at a wavelength of 550 nm was 1 nm, and a retardation Rth (550) in the thickness direction at a wavelength of 550 nm was 26 nm, and the SP value was 22 MPa ^1/2 .

(Formation of optically anisotropic layer)

The rubbing process was continuously performed to the cellulose acylate film produced above. At this time, the longitudinal direction and conveyance direction of the long film were parallel, and the angle which the film longitudinal direction (conveyance direction) and the rotation axis of a rubbing roller make was 72 degrees. In addition, if the film longitudinal direction (conveying direction) is 90°, and observed from the cellulose acylate film side, the counterclockwise direction is positive based on the width direction of the cellulose acylate film as a reference (0°). The axis of rotation was 18°. In other words, the position of the rotation shaft of the rubbing roller was a position rotated by 72 degrees clockwise with respect to the longitudinal direction of the cellulose acylate film.

The composition (A) for forming an optically anisotropic layer containing the following rod-shaped liquid crystal compound was applied on the rubbing-treated film using a die applicator, and the film on which the composition layer was formed was heated at 100° C. for 80 seconds. Then, the composition layer was irradiated with the light of a 365 nm LED lamp (Acro Edge Co., Ltd. product) at 40 degreeC under air (oxygen concentration: about 20 volume%) at the irradiation amount of 13mJ/cm< ² >.

Furthermore, the obtained composition layer was heated at 90 degreeC for 10 second.

Thereafter, the optically anisotropic layer 1 in which the orientation of the liquid crystal compound is fixed by irradiating the composition layer with light from a metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 55° C. under a nitrogen atmosphere (irradiation amount: 500 mJ/cm ² ) formed, and the optical film 1 was produced.

------------------------------------------------------------ -----------

Composition of the composition (A) for forming an optically anisotropic layer

------------------------------------------------------------ -----------

・The following rod-shaped liquid crystal compound (A) 80 parts by mass

・The following rod-shaped liquid crystal compound (B) 10 parts by mass

・The following rod-shaped liquid crystal compound (C) 10 parts by mass

Ethylene oxide-modified trimethylol propane triacrylate

(V#360, made by Osaka Yuki Chemical Co., Ltd.) 4 parts by mass

・Photoinitiator (Irgacure 819, manufactured by Ciba Japan) 3 parts by mass

・The following chiral agent (A) 0.42 parts by mass

・The following chiral agent (B) 0.38 parts by mass

The following polymerizable polymer (b-1) 0.5 parts by mass

・The following polymer (A) 0.08 parts by mass

·Methylisobutylketone 117 parts by mass

・Ethyl propionate 39 parts by mass

------------------------------------------------------------ -----------

Rod-shaped liquid crystal compound (A) (hereinafter, corresponding to a mixture of liquid crystal compounds)

[Formula 6]

Rod-like liquid crystal compound (B)

[Formula 7]

Rod-like liquid crystal compound (C)

[Formula 8]

Chiral agent (A)

[Formula 9]

Chiral agent (B)

[Formula 10]

Polymerizable polymer (b-1) (SP value: 23.2 MPa ^1/2 ) (In the formula, the numerical value described for each repeating unit represents the content (mass %) of each repeat with respect to all repeating units.)

[Formula 11]

Polymer (A) (In the formula, the numerical value described in each repeating unit represents the content (mass %) of each repeat with respect to all repeating units.)

[Formula 12]

<Example 2>

The optical film 2 was produced according to the procedure similar to Example 1 except having changed the polymer (b-1) into the polymerizable polymer (b-2).

Polymerizable polymer (b-2) (SP value: 23.7 MPa ^1/2 ) (In the formula, the numerical value described in each repeating unit represents the content (mass %) of each repeat with respect to all repeating units.)

[Formula 13]

<Example 3>

The optical film 3 was produced according to the procedure similar to Example 1 except having changed the polymer (b-1) into the polymerizable polymer (b-3).

Polymerizable polymer (b-3) (SP value: 21.2 MPa ^1/2 ) (In the formula, the numerical value described in each repeating unit represents the content (mass %) of each repeat with respect to all repeating units.)

[Formula 14]

<Example 4>

The same as in Example 1, except that the cellulose acylate film was changed to a modified methyl methacrylate-based resin film (trade name "Fine Cast Film RZ-30NA-S" by Toyo Kohan Co., Ltd.) (SP value: 20.5 MPa ^1/2 ) According to the procedure, optical film 4 was produced.

<Example 5>

Optical film 5 according to the same procedure as in Example 1, except that the cellulose acylate film was changed to a thermoplastic norbornene-based resin film (“Zeonoa” manufactured by Nippon Zeon Co., Ltd.) (SP value: 21 MPa ^1/2 ) made

<Example 6>

An optical film 6 was produced in the same manner as in Example 1 except that the polymer (b-1) was changed to the boronic acid monomer (b-4).

Boronic acid monomer (b-4) (SP value: 24.1 MPa ^1/2 )

[Formula 15]

<Comparative Example 1>

The optical film C1 was produced according to the procedure similar to Example 1 except having removed the polymer (b-1) in the composition of the composition (A) for optically anisotropic layer formation.

<Comparative Example 2>

An optical film C2 was produced in the same manner as in Example 1 except that the acrylamide monomer (b-5) was used instead of the polymer (b-1).

Acrylamide monomer (b-5) (SP value: 24.8 MPa ^1/2 )

[Formula 16]

<Comparative Example 3>

Optical film C3 was produced according to the procedure similar to Example 1 except having changed the addition amount of the polymer (X1) in the composition of the composition (A) for optically anisotropic layer formation to 11 mass parts.

<Evaluation>

(orientation)

The optically anisotropic layer in the optical film obtained in the cross nicol state in the polarizing microscope was observed, and the following reference|standard evaluated.

"A": No optical defect is observed.

"B": A level at which optical defects are slightly observed, but practically no problem.

"C": Many optical defects are observed and it is a level with a problem practically.

(Measuring method of TOF-SIMS)

Device and conditions

・Device: TOF-SIMSV (manufactured by ION-TOF)

Depth direction analysis: combined with Ar ion sputtering

Measuring range: Raster scan of 128 points each in one direction and the orthogonal direction

·Polarity: posi, nega

Imax, Iave, and Iwid were calculated according to the method described above. Moreover, it was confirmed whether the requirements 1 and 2 were satisfied according to the above-mentioned procedure.

(Cross Cut Test)

About the optically anisotropic layer of the obtained optical film, the crosscut test (checker tape peeling test) based on JIS D0202-1988 was implemented. Among 100 grids formed by grid-like cuts in the optically anisotropic layer, the number of grids peeled by pasting and peeling of cellophane tape ("CT24", manufactured by Nichiban Co., Ltd.) was counted and evaluated according to the following criteria.

"S": The number of grids to be peeled off is 0

"A": 1 to 30 grids to be peeled off

"B": 31 to 50 grids to be peeled off

"C": 51 or more grids to be peeled off

In Table 2, in the "Requirement 1" column, the case where the requirement 1 is satisfied is referred to as "A", and the case where the requirement 1 is not satisfied is referred to as "B".

[Table 2]

As shown in the said table|surface, it was confirmed that the optical film of this invention shows a desired effect.

From the comparison of Examples 1, 4, and 5, when a cellulose acylate film was used as the resin substrate, it was confirmed that the effect was more excellent.

From the comparison of Examples 1 to 3 and 6, when a specific polymerizable polymer was used as a specific compound, it was confirmed that the effect was more excellent.

From the comparison of Examples 1-3, when Imax/Iave was 50 or more, it was confirmed that the effect was more excellent.

10 optical film
12 Resin base
14 Optically Anisotropic Layer
16 composition layer

Claims (8)

An optical film having a resin substrate having an orientation regulating force, and an optically anisotropic layer disposed on the resin substrate,
The optically anisotropic layer includes a liquid crystal compound and a compound having a hetero atom that is different from the liquid crystal compound,
Let the surface on the side of the optically anisotropic layer of the optical film be the first surface, and the surface on the side of the resin substrate of the optical film as the second surface, from the first surface toward the second surface side, An optical film that satisfies both the following requirements 1 and 2 when the components in the depth direction of the optical film are analyzed by the time-of-flight secondary ion mass spectrometry while irradiating.
Requirement 1: A resin constituting the resin substrate with a depth position most located on the second surface side showing a secondary ionic strength that is 80% of the maximum strength of the secondary ionic strength derived from the liquid crystal compound as position A When the depth position most located on the first surface side showing the secondary ionic strength that is 80% of the maximum intensity of the derived secondary ionic strength is the B position, any one between the A position and the B position The depth position of WHEREIN: The maximum value Imax of the secondary ionic strength derived from the compound which has the said hetero atom is shown.
Requirement 2: The depth position showing the maximum value Imax of the secondary ionic strength derived from the compound having the hetero atom is the peak position, and the first surface side from the peak position showing the secondary ionic strength half of the maximum value Imax is, the depth position closest to the peak position is the position C, the secondary ionic strength is half of the maximum value Imax, is on the second surface side from the peak position, and the depth position closest to the peak position When , is the D position, the distance between the C position and the D position is 100 nm or less. The method according to claim 1,
The optical film wherein the compound having a hetero atom has at least one selected from the group consisting of a urethane group, an ester group, an amide group, and a boronic acid group. The method according to claim 1 or 2,
The optically anisotropic layer,
A liquid crystal compound having a polymerizable group;
The optical film which is a layer formed using the composition which is different from the liquid crystal compound which has the said polymeric group, and contains the polymeric compound which has a polymeric compound while having a hetero atom. 4. The method according to claim 3,
The optical film in which the polymeric compound which has the said hetero atom and has a polymeric group contains the repeating unit which has a polymeric group, and is a polymer|macromolecule which has a hetero atom. 5. The method according to any one of claims 1 to 4,
When the average intensity of the secondary ionic strength derived from the compound having a hetero atom from the first surface to the A position is taken as the average value Iave, the maximum value Imax and the average value Iave are the relationship between the formula (A) Satisfying, optical film.
Equation (A) 1.3≤Imax/Iave 6. The method of claim 5,
The Imax/Iave is 50 or more, the optical film. 7. The method according to any one of claims 1 to 6,
The optical film, wherein the distance between the C position and the D position is 50 nm or less. 8. The method according to any one of claims 1 to 7,
The optical film in which the said resin base material contains a cellulose acylate.

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